Comprehension and inferences

Vivi is 19 months old. She doesn't say a lot of words, but her comprehension is remarkable.

A couple days ago, Vivi was anxious to go on a walk to the swings. I said (more to myself than to her), "I am going to go upstairs and get my sunglasses and then we can go." As I walked away, Vivi started urgently grunting and gesturing - pointing to my head -- to tell me that my sunglasses were on my head. I was astounded by the comprehension that had to happen for this exchange.

She had to hear my words and understand each one to comprehend what it was that I was saying. She then had to infer that, since I said I was going upstairs to get my sunglasses, that probably meant that I thought my sunglasses were upstairs. She then had to know where my sunglasses were (on my head) and infer that I must not know where they are and that she could help me (and hence the urgent need to communicate).

I would not have been surprised at all if I had asked, "Vivi, where are my sunglasses?" and she was able to point at them. What I was surprised by was her ability to infer something (that I didn't know where my sunglasses were) very different from what I actually said and communicate appropriately.